Home
Class 12
MATHS
Two lines L(1): x=5, (y)/(3-alpha)=(z)/(...

Two lines `L_(1): x=5, (y)/(3-alpha)=(z)/(-2)`
`L_(2):x=alpha, (y)/(-1) =(z)/(2-alpha)` are coplanar. Then, `alpha` can take value (s)

A

1, 4, 5

B

1, 2, 5

C

3, 4, 5

D

2, 4, 5

Text Solution

AI Generated Solution

The correct Answer is:
To determine the values of \( \alpha \) for which the lines \( L_1 \) and \( L_2 \) are coplanar, we will use the condition involving the determinant of the direction ratios and the coordinates of points on the lines. ### Step-by-Step Solution: 1. **Identify the equations of the lines:** The equations of the lines are given as: \[ L_1: x = 5, \quad \frac{y}{3 - \alpha} = \frac{z}{-2} \] \[ L_2: x = \alpha, \quad \frac{y}{-1} = \frac{z}{2 - \alpha} \] 2. **Convert the equations into parametric form:** For line \( L_1 \): - Let \( z = -2t \) (parameter \( t \)) - Then \( y = (3 - \alpha)t \) - The parametric form is: \[ (x, y, z) = (5, (3 - \alpha)t, -2t) \] For line \( L_2 \): - Let \( z = (2 - \alpha)s \) (parameter \( s \)) - Then \( y = -s \) - The parametric form is: \[ (x, y, z) = (\alpha, -s, (2 - \alpha)s) \] 3. **Set up the determinant condition for coplanarity:** The lines are coplanar if the following determinant is zero: \[ \begin{vmatrix} 5 - \alpha & 0 & 0 \\ 3 - \alpha & -1 & 2 - \alpha \\ -2 & 0 & 0 \end{vmatrix} = 0 \] 4. **Calculate the determinant:** The determinant simplifies to: \[ (5 - \alpha) \begin{vmatrix} -1 & 2 - \alpha \\ 0 & 0 \end{vmatrix} - 0 + 0 \] The determinant of the 2x2 matrix is zero, so we focus on the first term: \[ (5 - \alpha)(-1)(0) - (3 - \alpha)(0) + 0 = 0 \] This leads to: \[ (5 - \alpha)(3 - \alpha)(2 - \alpha) = 0 \] 5. **Solve for \( \alpha \):** The equation \( (5 - \alpha)(3 - \alpha)(2 - \alpha) = 0 \) gives: \[ \alpha = 5, \quad \alpha = 3, \quad \alpha = 2 \] Thus, the values of \( \alpha \) for which the lines \( L_1 \) and \( L_2 \) are coplanar are \( \alpha = 2, 3, 5 \). ### Final Answer: The values of \( \alpha \) are \( 2, 3, 5 \).
Promotional Banner

Topper's Solved these Questions

  • QUESTION-PAPERS-2014

    BITSAT GUIDE|Exercise MATHEMATICS|45 Videos
  • QUESTION-PAPERS-2016

    BITSAT GUIDE|Exercise MATHEMATICS|45 Videos

Similar Questions

Explore conceptually related problems

Two lines L_(1) : x=5, (y)/(3-alpha)=(z)/(-2) and L_(2) : x=alpha, (y)/(-1)=(z)/(2-alpha) are coplanar. Then, alpha can take value(s)

Two lines L_(1):x=5,(y)/(3-alpha)=(z)/(-2) and L_(2):x=alpha,(y)/(-1)=(z)/(2-alpha) are coplanar.Then alpha can take value (s) a.1 b.2 c.3 d.4

If for some alpha in R, the lines L_1 : (x + 1)/(2) = (y-2)/(-1) = ( z -1)/(1) and L_2 : (x + 2)/(alpha) = (y +1)/(5 - alpha) = (z + 1)/(1) are coplanar , then the line L_2 passes through the point :

cosider Lines L_(1):(x-alpha)/(1)=(y)/(-2)=(z+beta)/(2)*L_(2):x=alpha,(y)/(-alpha)=(z+alpha)/(2-beta) Plane p:2x+2y+z+7=0. Let line L_(2) line in plane p, then

Let L_(1) and L_(2) be the foollowing straight lines. L_(1): (x-1)/(1)=(y)/(-1)=(z-1)/(3) and L_(2): (x-1)/(-3)=(y)/(-1)=(z-1)/(1) Suppose the striight line L:(x-alpha)/(l)=(y-m)/(m)=(z-gamma)/(-2) lies in the plane containing L_(1) and L_(2) and passes throug the point of intersection of L_(1) and L_(2) if the L bisects the acute angle between the lines L_(1) and L_(2) , then which of the following statements is /are TRUE ?

The complete set of values of alpha for which the lines (x-1)/(2)=(y-2)/(3)=(z-3)/(4) and (x-3)/(2) =(y-5)/(alpha)=(z-7)/(alpha+2) are concurrent and coplanar is

Line (x-2)/alpha=(y-2)/(-3)=(z+2)/2 lies in x+3y-2z+beta=0 then alpha+beta= ?

Suppose the line (x-2)/(alpha) = (y-2)/(-5) = (z+2)/(2) lies on the plane x + 3y - 2z + beta = 0 . Then (alpha + beta) is equal to ________.

BITSAT GUIDE-QUESTION-PAPERS-2015-MATHEMATICS
  1. Tangents are drawn from the origin to the curve y=cos X. Their points ...

    Text Solution

    |

  2. The slope of the tangent to the curve y=e^x cosx is minimum at x= a,0 ...

    Text Solution

    |

  3. Two lines L(1): x=5, (y)/(3-alpha)=(z)/(-2) L(2):x=alpha, (y)/(-1) =...

    Text Solution

    |

  4. The eccentricity of an ellipse with its centre at the origin is (1)/(2...

    Text Solution

    |

  5. The function f(x)=x/2+2/x has a local minimum at x=2 (b) x=-2 x=0 (...

    Text Solution

    |

  6. If y=(x+sqrt(1+x^2))^n then (1+x^2)(d^2y)/(dx^2)+x(dy)/(dx)

    Text Solution

    |

  7. If lim(x to oo) x sin ((1)/(x)) =A and lim(x to 0) x sin ((1)/(x)) =B,...

    Text Solution

    |

  8. If a and b (ne 0) are the roots of the quadratic x^(2)+ax+b=0 then the...

    Text Solution

    |

  9. If 0 lt x lt pi /2 then

    Text Solution

    |

  10. The degree of the differential equation satisfying sqrt(1-x^(2))+sqr...

    Text Solution

    |

  11. Let f(x) be a polynomial of degree three f(0) = -1 and f(1) = 0. Also,...

    Text Solution

    |

  12. The domain of the function f(x)=(sin^(-1)(x-3))/(sqrt(9-x^(2))), is

    Text Solution

    |

  13. If the lines p1x+q1y=1+q2y=1 and p3x+q3y=1 be concurrent, show that th...

    Text Solution

    |

  14. Area of the circle in which a chord of lengthsqrt2 makes an angle pi/2...

    Text Solution

    |

  15. If (cosA)/(cosB)=n and (sinA)/(sinB)=m,then (m^(2)-n^(2))sin^(2)B=

    Text Solution

    |

  16. If complex number Z(1), Z(2) and 0 are vertices of equilateral triangl...

    Text Solution

    |

  17. If rho={(x , y)|x^2+y^2=1, x , y in A}.Then , rho is

    Text Solution

    |

  18. A line line makes the same angle theta with each of the x and z-axes....

    Text Solution

    |

  19. If in a binomial distribution n=4,\ P(X=0)=(16)/(81),\ t h e n\ P(X=4)...

    Text Solution

    |

  20. Let f:R to R be a function such that f(x+y)=f(x)+f(y)"for all", x,y in...

    Text Solution

    |